The present invention relates to a skylight curb seal and method, particularly for installing a skylight to a site-built curb wherein the dimensions of the curb and skylight are not required to be predetermined or matched to a high degree of tolerance.
Skylights continue to be popular features in new homes as well as popular additions to existing homes. They present some difficulties, however, particularly in sealing to the structure so as to prevent the entry of wind and moisture.
Skylights are typically attached to a curb, which is generally a wooden frame that is anchored to and extends upwardly from the roof of the structure. The curb is typically fabricated on-site by the roofing contractor. A seal between the skylight and the curb is typically formed with a caulking compound. Often the caulk dries, shrinks and hardens, and loses its compliance while at the same time detaching from the skylight and curb, so that it may lose much, if not all, of its effectiveness over time. Further, to avoid tolerancing problems between the typically onsite and hand-built curb and the manufactured skylight, the bead of caulk must be positioned on the top of the curb, rather than on its sides. As the sides of the curb are surrounded by metal flashing that does not extend to cover the top of the curb, the caulk so applied leaves space between the flashing and the caulking that is unprotected. This space is a source of leakage from moisture wicking or draining into the space between the flashing and the side of the curb.
As an alternative to caulk, a foam-backed tape is often employed which can eliminate the problem of hardening and shrinkage. However, the tape may not adhere well to the curb, or may lose its adhesion over time. Further, like caulk, foam-backed tape also fails to prevent access by wind and moisture to the side of the curb, and the space between the flashing and the side of the curb. Moreover, neither caulk nor tape can be effectively applied to a wet curb, hampering skylight installation in inclement weather.
As another alternative for sealing a skylight to a curb, a gasket is sometimes provided that includes compliant members for sealingly filling the space between an otherwise loosely fitting skylight and curb. For example, Guhl, U.S. Pat. No. 5,199,234, proposes a gasket resting on the curb having weatherstrip extensions that project upwardly against skylight frame that acts as a cover. This approach provides advantages over sealing with caulk; however, the gasket of Guhl also had disadvantages. For example, the gasket is formed as a complete, closed form unit, so it cannot be modified on-site to fit an existing curb. Therefore, the tolerance between the skylight and the curb must remain close, increasing costs and decreasing flexibility. Another disadvantage of the gasket of Guhl is that the utility of its weatherstrip extension depends on the pre-manufacture of a substantially parallel surface on the frame. Such xe2x80x9cinward protrusionsxe2x80x9d are provided in some manufactured skylight/curb assemblies but are not typically provided in skylights designed for use with site-built curbs.
Accordingly, there is a need for a skylight curb seal and method that provides for sealing a variety of existing manufactured skylights of arbitrary nominal size to curbs that need not be matched to the size of the skylight to a close tolerance, to provide for increased sealing effectiveness and construction flexibility, and decreased cost.
A skylight curb seal according to the present invention solves the aforementioned problems and meets the aforementioned needs by providing an elongate gasket material having substantially constant cross-sectional shape and dimensions along its length. The gasket material has a substantially xe2x80x9cLxe2x80x9d shaped backbone portion with one or more compliant members extending therefrom. With reference to its position installed between a curb and a skylight placed over the curb, the backbone portion has a substantially horizontally extending leg, adapted for making contact with the top of the curb, and a substantially downwardly extending leg, adapted for disposition between the side of the curb, more particularly the side of flashing disposed adjacent the side of the curb, and the side of the skylight. The downwardly extending leg includes one or more downwardly depending compliant members. A first compliant member extends downwardly toward and comes into contact with the side of the skylight. A second compliant member extends downwardly toward and comes into contact with the flashing adjacent the side of the curb. The lengths of the compliant members are provided to permit the compliant members to accomodate a wide variation in the dimensions of the skylight with respect to the dimensions of the curb. As the compliant members are downwardly depending, wind acting against the compliant members forces-the compliant members against the curb and skylight surfaces with which they come into contact, increasing the effectiveness of sealing during windy conditions.
Therefore, it is a principal object of the present invention to provide a novel and improved skylight curb seal and method.
It is another object of the present invention to provide a skylight curb seal and method that provides for sealing a variety of different skylights on the construction site.
It is yet another object of the present invention to provide a skylight curb seal and method that provides for effectively sealing skylights having a variety of shapes and sizes.
It is still another object of the present invention to provide a skylight curb seal and method that provides for effectively sealing a skylight to a site-built curb that is not matched to the skylight with a close tolerance.
It is a further object of the present invention to provide a skylight curb seal and method that provides for increased construction flexibility and decreased cost.
The foregoing and other objects, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the following drawings.